[PATCH v3 0/4] git add --resolved

When you are the maintainer of a project and make many merges day
in, day out, a lot of your time is spent resolving conflicts and
adding the results to the index.  It is not unusual to have local
changes in your working tree that are unrelated to any particular
merge [*].  In such cases, 'git add -u', which adds all changes in
the working tree to the index, does not help much.

Here is a new option for 'git add' that lets you add paths with
resolved conflicts to the index, while keeping unrelated local
changes out.

The first three patches perform preliminary refactorings.

 - [1/4] is a totally unrelated code cleanup that almost disappears
   when viewed with 'git show -w', but it was an eyesore to have so
   many lines with broken indentation while working in the vicinity.

 - [2/4] consolidates a helper function to determine whether a line
   is a conflict marker (replacing two slightly different
   definitions).

 - [3/4] introduces a helper that makes registering path removals
   from the index as easy as adding them, complete with automatic
   '--dry-run' and '--verbose' support.

The fourth patch implements the new feature.

 1/4: read-cache: reindent
 2/4: merge-ll: consolidate conflict marker scanning logic
 3/4: read-cache: add remove_file_from_index_with_flags()
 4/4: add: introduce '--resolved' option


The only change since v2 is to fix the test under BREAKING_CHANGES,
where the tests are run with a future default initial branch name of
'main'.  Instead of assuming that the initial branch is named
'master' when returning, we instruct 'checkout' to return to the
previous branch, i.e., '@{-1}'.


[Footnote]

 * This is not limited to my own workflow. An earlier message on
   this topic worth mentioning is:

   https://lore.kernel.org/git/CA+55aFxP8j7YbYaRXt-8Y0n8cHafB=FPKMy8gKFYH5QsKX4S=Q@mail.gmail.com/

 Documentation/git-add.adoc |  10 +++-
 builtin/add.c              |  92 ++++++++++++++++++++++++++++---
 diff.c                     |  25 +--------
 merge-ll.c                 |  56 +++++++++++++++++++
 merge-ll.h                 |   2 +
 read-cache-ll.h            |   3 ++
 read-cache.c               |  89 +++++++++++++++++-------------
 rerere.c                   |  38 +++----------
 t/meson.build              |   1 +
 t/t2207-add-resolved.sh    | 108 +++++++++++++++++++++++++++++++++++++
 10 files changed, 323 insertions(+), 101 deletions(-)
 create mode 100755 t/t2207-add-resolved.sh

Range-diff against v2:
1:  b0643ed516 = 1:  414219a89a read-cache: reindent
2:  4533fa4da1 = 2:  f64ad26d1f merge-ll: consolidate conflict marker scanning logic
3:  dbf70c2d3a = 3:  1431d0bfdb read-cache: add remove_file_from_index_with_flags()
4:  033a3d2526 ! 4:  42fb33200a add: introduce '--resolved' option
    @@ t/t2207-add-resolved.sh (new)
     +	echo "theirs 3" >file3.txt &&
     +	git commit -a -m theirs &&
     +
    -+	git checkout master
    ++	git checkout @{-1}
     +'
     +
     +test_expect_success 'git add --resolved refuses files with conflict markers' '

-- 
2.55.0-599-g5cacd2ad51